Semiautomatic rifle



Jan. 14, 1930. c. D. MEYER 1,743,472

SEMIAUTOMATIC RIFLE Filed Dec. 8, 1924 9 Sheets-Sheet l fig Jay. 14, 1 930. c. n. MEYEfi sEmIAUfdmATIc RIFLE' Filed Bias. 8, 1924 9 Sheets-Sheet 2 ENTOR J TORNEY Jan. '14, 1930.

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SEMIAUTOMATIC RIFLE flied Dec. 8. 1924 9 Shets-Shet e ATTORNEY Jan. 14, 1930. c. D. MEYER 1,743,472

Q SEMIAUTOMATIC RIFLE Filed Dec. 8. 1924 9 Sheets-Sheet ATTORNEY 7 Jan. 14,1930. MEYER 1,743,472

I SEMIAUTOMATIC RIFLE Filed Dec. 8, 1924 9 Sheets-Skies: 8

ATTORN EY Jan. 14, 1930. c. D. MEYER SEMIAUTOMATIC RIFLE Filed Dec. 8, 1924 9 Shaets-Sheet 9 iiiiiaii 32%ij iaejiz i INVE OR ATTORNEY Patented Jan. 14, 1930 I CHARLES D. MEYER, F SEATTLE, WASHINGTON SEMIAUTOMATIO RIFLE Application filed December-.8 1924. Serial No. 754,458.

those heretofore proposed.

. With these and other objects in view the lnventlon consists in the novel details of construction and combinations of parts more fully hereinafter disclosed and particularly pointed out in the claims.

Referring to the accompanying drawing forming a part of this specification in which the likenumerals designate like parts in all the views, in which,-

Figure 1 is a general top view of the assembled rifle showing the action closed gate cover down and safety on. Fig. 2 is a right hand side view of the assembled rifle, gate cover down and safety on; it also shows'the system of ventilation. Fig. 3 is an enlarged plan view of the rifle action shown in Fig. 1. Fig. 4 is also an enlarged side view of the action shown in Fig. 2. Fig. 5-is a vertical longitudinal section of the rifle action shown in'Fig. 4 illustrating the mechanism assembly of its component parts in their normal position. Fig. 6 is a rear view of the rifle shown in Figs. 1 and 2. Fig.7 is a horizontal section of Fig. 3' with breech bolt and parts associated therewith illustrated in retractedpositions. Fig. 8 is a rear view of the assembled rifle showing the safety lever down and gate cover open. Fig. 9 is a side elevation, partly in section, of the (power cylinder to show itscomponent parts it also illustrates a fragmentary part of the rifle barrel to show their relative positions when assembled to the rifle action shown in Fig. 4. Fig. 10 is a I vertical longitudinal section of the front end of the rifle to show the gas retarder. Fig.

' 11 is a fragmentary vertical section of the receiver showing details hidden by the breech bolt in Fig. 5. Fig. 12 is the forward end view of Fig. 1 1. Fig. 13 is four side views of the bolt shown-in different rotary positions. Fig. 14 is a view partly in section and partly in plan, showing the bolt and a portion of the operatingslide. Figs. 1-5, 16 and 17 are development views of the peripheral surfaces of the rear portion of the olt shown in Fig. 13

to illustrate the grooves thereof with respect to the operating slide lugs which are represented by shaded areas in Figs. 15, 16 and 17. Fig. 18 is a right side elevation of the operating slide. Fig; 19 is a front end view of Fig. 18.". Fig.20 is aview partly in plan and artly in section of the firing pin assembly. ig. 21 is an elevational view of the firing pin assembly with the main spring com ressed.

Fig.22 is a detail view, partly in si e elevation and partly vertical, of portions of the magazine to disclose thebolt stop; Fig. 23 is a sectionalview taken substantially on line 23-23 of Fig. 22; and Fig. 24 is a fragmentary plan view of Fi 23. Figs. 25, 26, and 27 are side views of ti sear-and-trigger mechanism illustrating the progressive position of the respective parts. Fig. 28 is a plan view of the breech bolt power piston assembly. Fig. 29 is'a rear view of the rifle with the receiver cap and breech bolt power piston assembly removed.

The locking mechanism in this automatic load ing rifle is practically the same as the one found inthe Springfield, model of 1903, which consists of a bolt 1, Fig. 5, having the locking lugs 2 and 3 engaging the recesses 4 and 5 1n the receiver ring 6 by means of a rotary motion of the bolt. This rotary motion is communicated to the bolt 1 by the operating slide 7 whichhas two internal operating lugs 8 and 9, Figs. 18 and 19. These two lugs are of suitable length and width to fit the operating grooves 10 and 11 provided therefor on the periphery and diametrically opposite side of the rear portion of the bolt.

As best shown in Fig. 13, each of said grooves has an angle or pitch such that when the operating slide is pulled to the rear one inch, approximately, the bolt is rotated one quarter of a turn.

These grooves 10 and 11 are offset circumferentially of the bolt and having a widened communicating portion which constitutes a neutral region and provide shoulders 12 and 13 shown in Fig. 13 and also in the development views Figs. 15, 16 and 17. Said neutral region or space allowing the operating lugs 8 and 9 a small longitudinal movement within such neutral region, as indicated by a and b Fig. 17 w ere the 10 in Figs. 16 and 17, without imparting" any rota motion to the bolt 1 when the operating s ide 7 is reeiprocated within the receiver grooves or races 16.

5 The neutral region between the shoulders 12 and 13 in the grooves 10 and 11 eliminate or annul the rotary motion of the bolt when the operating lugs 8 and 9 are within the neutral s ace or region inclosed by the sides of said 0 set portions of the grooves and between the shoulders 12 and 13, as represented in Figs. 16 and 17. The reciprocating movement of the operating slide 7 along the receiv er groove' 16 (Fig. -5) will cause the operate ing lugs 8 and 9 to move'in' a rectilinear direction or arallel to the lines m and y in Figs.

15, 16 an 17 In Fig. 5the breech bolt is illustrated in its closed position; the develop-; ment view for which position is-shown in Fig.

15 wherein the two. operating lugs 8v and 9 are at the forward end of their travel and fit into the grooves 10 and 11, and thus posi-' tioned the bolt cannot rotate either way it is thereby locked in closed position. However, the operatin slide can be-moved to the rear .by hand an in doing so will force the operating lugs 8 and 9, which are integral with it, to travelin a rectilinear direction or-parallel to the lines a: and y in the Figs. 13, 15, 16 and 17 causin the grooves 10 and 11 to be moved to the le a distance 1'1- Fig. 16 equal to a uarter of a turn of the bolt. At this instant free to' e reciprocated together with an ab sence of rotary motion without being locked far as they go or to the open positionin Which'it is illustrated in Fig. 7.

the operating slide ahead by means ofthe o erating handle 17 to close the breech bolt an will cause the operating lugs 8 and out, however, imparting any rotary or axial movement to the bolt, because said lugs 8 and 9 being the neutral ace common to both grooves can be tr to theri I t sides thereof, as represented in 'tudinal d stance a and the an r distanees'rr (Fig. 16) is equal to lugs 8 and 9 are ar- 17- where the o r shc m ld e i' s 12.- A further ush rested by the on the handle 17 will cause the operating ugs 8 and 9 to close the breeclfbolt without, however, i mparting to it rotary motion until together. The can thus bepulled back asv 9 to move ahead a distance a (Fig. .16) witherred from the left sides Fig. 16) of the grooves 10 and 11- the distances 6 and rr, respectively in Fig. Y

after it is completely closed and ready to lock; this change occurs when the locking lug 2, which has its front face 18 (Fig. 13) machined at a suitable angle, engaged axially the cam having a helical face 19, Figs. 6, 7

and 11, thereby causing arotary movement to the said bolt sufiicient to disengage the 0 crating lugs 8 and 9 from the shoulder 12,

ig. 17. Sand operating lugs nowbeing in line to register with the grooves 10 and 11 presses against their right sides complete the locking movement of said bolt; the action is; thus closed and looked as represented in Fig.

5 and also in the development Fig. 15.

It will be seen by the above explained action that there are no means whatever to lockv or prevent the breech bolt from rotating during its reciprocating motion, that it is absolutely free from rotating movement. That its opening movement is completed by the operating lugs which are in contact throughout their lengths with the left sides of the respective operating grooves, see Figs. 15 and 16, prolongs the usefulness of the opposed parts and with a minimum of stress and wear.

In itsclosing motion, the operating lugs are also in contactthroughout their lengths with the right hand sides of the grooves therebypermitting the breech bolt to be rammed home even with a considerable force without danger of breaking any of its parts. The helical cam 19, which 1s used as a disengaging cam, is also used as an extractin cam but only'when said action is employe as a hand operated arm. This cam 19,- more over, which can only receive glancing blows from the locking lug 2 makes an ideal com bination for a semi-automaticrifle action, as it is not subject to dead shocks, that is to -say-,metallic surfaces meeting head onmakes this action extremely smooth. In actual, practice, the opening movement "can not be heard and its closing is hardly audible.

, The interior of the bolt 1 is bored asshown in Fig. 14 to accommodate the firing pin and main spring assembly, as shown .by dotted lines in Fig. 28. At its rear end, said bolt is externally screw threaded as at 20to interlock with internal threads 29 provided in the bolt sleeve 21, as shown in 20 and 21.

' The head of the bolt 1 in this invention is provided witha helical face 18 on its' In 2 (Fig- 13) to coact with the cam19 to e ect two important functions first to produce a rotary movement to the bolt in ail-"axial movement thereof engages the cam and, second, to produce, an axial movement .to the bolt when the latterrrotatably engages the cam.

The extractor 22 Figs...4,"14 and 22 has a head substantially similar to thatpf the Springfield,-'model M1903. Its-rear part,

however, is provided with a spring 14,

'de 23 of-the op- 1t itself when-the inc The operating slide 7, see Fig. 18, is tubular in shape provided interiorly with the two Operating lugs 8 and9 which are also shown in the development views, Figs. 15, 16 and On its exterior and disposed at diametrically opposite sides are the guides 23 and 24 (Figs. 18 and 19) the guide 23, on the righthand side, is provided with a socket which serves-as a way for the extractor tail 14. The guide 24, which is located at the lefthand side of the slide, is grooved its full length to enable it to pass theejector 25,

V. Fig. 7..

These guides 23 and 24 are, moreover, arranged to slide in the receiver grooves 16, Figs. 5 and 7. I

At its rear ,end the operating slide 7 is provided with an operating handle comprising an arm 26 projecting from the side 'guide 23 and terminating in a knob 17 as best shown in Figs. 18 and 19. At about its midlength the arm 26 is formed toprovide at its underside a boss. 27 which is bored and tapped to receive an end ofa piston rod 28, shown in Figs. 4, 7, 9 and 28.-

, Thebolt sleeve 21, Figs. 5, 20 and 21, is of the same outside diameter as the rear part of the bolt, its front end is interiorly threaded as denoted by 29 for the purpose of interlocking with the thread. 20 rovided at the rear of the bolt 1, as shown in Fig. 5. Said bolt sleeve is bored for the passage of the firing pin 30 which is screwed into the cocking piece 31. Surrounding said firing pin is the main spring 32 one end of which is held in a slot 33 milled in the firing pin flange 34 and its other end engages in a hole 35 provided in the bolt sleeve as shown.

At its rear end the bolt sleeve is bifurcated to provide two cheek elements 37 with plane inner surfaces at opposite sides of a slot 36 and between which the cocking piece 31 slidingly fits. Each cheek 37 is provided with a series of notches 38 (Figs. 5, 2, and 21) to afford a non-slip hand gripping surface. The cockin piece 31 has its opposite sides 39 plane to fi t against the plane inner surfaces of the cheeks 37 of said bolt sleeve 21. The bolt sleeve has also at its rear end a flange 40 of the same diameter, or nearly. so,"a's the diameter of the main body of the operating slide 7, Fig. 5, and has at its under side a cocking nose 41.

' The bolt stop 42 (Figs. v22', 23 and 24) is located in and at the rear of the-magazine well, its housing 43 forming the back wall of said well. At each side oftlle stop 42 and integral with it are two tubular. plungers 44 (Fig. 23) acting as guides. On the inside of said plungers are located springs 45 which are held under. compression by the. screw plugs 46. The plungers 44 have at their lower end extensions 47 which project below the magazine floor plate 138. I This bolt stop 42 is limited in its travel downward by the lower ends of the plunger 44 engaging shoulders provided thereon in the housing 43, and its upward travel is limited by the screw plugs 46 which are regulated to allow but a small movement of about one-eighth of an inch. When the magazine is loaded with one or more cartridges the bolt stop 42 is held down by the two springs 45 in the position shown in Figs. 22 and 23. However, when thelast shot is fired, or the magazine is empty, the finger 49 of the magazine follower 50, which extends into the slot 51, under the tension ofthe magazine spring 52 elevates the stop 42 in front of the bolt face, as shown by] dotted lines 53 in Fig. 22, thereby holding the bolt in the open position in which it is represented in Fig. 7

The interior details of the receiver, forward of dotted line 54-54 Fig. 11, are similar to the Springfield, model of 1903, with the exception of the cam which, in the present invention, has a helical face '19 located in the receiver ring 6 instead of at the back of the, receiver bridge, above referred to, and back of the line 54-54the receiver is extended as shown in Figs. 3 and 4 which show the exterior details. In Figs. 5 and 7 are shown the interior details of the said extension, its purpose being to guide the breech bolt in its rearward ti'avel. It is accordingly bored and has the longitudinal grooves 16 in which slide the locking lugs 1 and 2 and also the operating slide guides 23 and 24, shown in Figs. 5 and 7. It has also at its bottom a guideway 55, for the cocking piece nose 41. At its rear end the receiver is threaded to receive the receiver cap 56 which is made hollow and adapted to be filled with a resilient material (not shown) such as cork for use as a buffer to thebreech bolt assembly. This receiver cap 56 is provided with a handle 57 at the end of which is a knob 58 having in its under side a recess within which engages the tapering upper end of .a spring actuated plunger 59 which is located on the center line of the receiver tang 60 to serve as a lock with respect to said receiver cap.

At the .left side of the said receiver is located the ejector housing 61 containing the %jectozr 25, ejector pin 62 and ejector spring 63,

cording to the present invention, the receiver is formed or constructed to rovide a cylindrical extension 64 at the orward righthand side of said receiver as shown in 1903 model,

in Figs. 1, 2, 3 and 4, and immediately back rear sight, not shown.

receiver 1s made wing plug 68 has a wing or thumb piece 70 and a short dowel 71 which fits into a hole 7 2 provided for it in the boss 27 of the operating arm 26, Figs. 4 and 19.

Above the cylindrical extension 64 (Fig. 43 the receiver is cut away like the Spring el for side ejection as illustrated of said out there isthe bridge 73, Figs. 4

and 7. At the rear of this bridge 73 is the gate opening 74 through which the operating handle arm 25 operates Fig. 4. This gate opening "extends to the rear end. of thereceiver, as shown inFigs."7 and 29, said gate opening being provided with a gate cover 75 which is hinged to the upper side of thesaid gateopening through the medium of apertured lugs 76- -77 through which extends a hinge pin 78. Surrounding the hinge pin 78 are two springs 79-80 so wound and installed that their reaction will tend to force the gate cover 75 open and against the stop 81 as shown 1n Figs. 8 and 29. This gate cover 75 when closed, as shown in Figs. 2 and 4,.

protectsthe action mechanism'from the entrance of sand, rain or dirt, and alsoacts as a lock to the breech bolt assembly. It will be seen in Figs. 2 and 4 that this gate cover is directly behind the operating handle arm 26 thus preventing the accidental opening of the action when the rifle is drop as is done in rifle exercise of military organi--. zations. f

The top of the receiver is finished as shown in Figs. 1, 2, 3, and 4, the flat surface 82 of whichis provided for the emplacement of a The underside of the to accommodate the sear 83 with its pin 84 and the trigger bracket 85 which is secured to the receiver by the two "screws 138-139.

Said trigger bracket 85v is made .of two housings integral with the base, one-half of which is shown in Fig. 5. Between these twohousings is located the trigger 86 .and the forked end of the sear link 87,- the upper fork 8 8'of which rests or'is supported by thesafety cam shaft 89 which carries the cam 90.

This cam shaft 89 is rotated by the safety lever 91, Fig. 4, having a lever 91 being secured to the cam shaft 89 by the pin 93 in such a. manner that the cam and thelever 91 are similarly oriented so that when the cam 90 is in the position shown in Fig.5 the safety lever 91 will be in the position' in which it is shown by dotted lines 94 in Fi .4 which is the firing position or ready.

y turning the lever 91 up to the position in which it is shpwn inJFigs. 4 and 6 causes the cam 90 (Fig. 5) to raise the forked end of the sear link 87 thereby disengaging it from the. trigger nose 95. which is the position of safety-or safe, see dotted lines Fig. 5. :The' safety lever 91 also serves as a lock-to the gate cover 75 (Fig. 4) .when

ped on its butt fluted head 92, the safety the lever 91 in front" of the cover 75 thereby keeping it shut, said gate cover 7 5, subject to the action of its springs, in turn, tends to keep the safety lever locked, thus affording mutual locking relation with respect to the safety lever and-the gate cover.

The trigger and'sear mechanism (Figs. 5, 25, 26 and 27) is composed of the sear 83 pivoted on the p1n84 and having the sear stop 96, the arm 97 to which is attached the sear link 87 by means of the pin 98. 87 is provided with an apertured lug 99 to which is attached an end of the combination This sear link sear and trigger spring 100 whose other end is attached to the trigger is provided with a detent 101 adjacent to its rear end which is forked, as shown, one arm of which 88 rests on the safety cam shaft 89 and its other arm 102 is suspended therefrom, as shown in Figs. 5, 25, 26 and 27. I "The trigger 86 has itsnose adapted to en-. gage the detent 101 of the sear link 87. Said trigger is provided with a spur 103 which carries the spur roller 104 and held by the pin 105. The trigger heel 107 .which bears against the end of the trigger guard slot 108 (Fig. 5) limits its forward travel. Except as above described the trigger may be of standard type and is connected to the trigger bracket 85 by means of a pin 104 upon which it oscillates. I This trigger and sear mechanism assembly is illustrated in Fig. 5 in which it is shown in its normal relation, where it will be seen that the sear-trigger spring which is under tension acts to pull the lower part of the trig-,

ager ahead and the sear-link back causing the position there is a small clearance between the trigger nose 95 and the detent 101 to allow the sear link to be raised or lowered or oscillate around the pin 98 when the safety cam 90 is rotated by means of the safety lever 91 from its safe position, full line in Fig.

lug 106. This link in which it is represented by 4, is movable into its ready position 94,indica'ted by dotted lines in the view, or vice versa.

Due to the singularity at which the spring 100 is disposed with respect to the sear link fulcrum and other supports, its tendency is to pull and keep said link down to the position illustrated by full line .in Fig. 5. Now, if by means of the operating handle 17, Fig. 6, the

breech bolt assembly is pulled to the rear from the position shown in Fig. 5 the cocking piece nose 41 will depress the sear 83 when passing over it, but which will return instantly to the normal position as soon as the nose 41' is to therearof the said sear 83. On returningthe breech bblt to close position,'however,'.the'

cocking piece nose-41 will remaimhooked be in Fig. 25, theactlonthen is said tobe cocked.

bind the sear 83 as shown by dotted-line'110 maasva To release the action or fire the gun bya finger presser against the bow of thetrigger 86, this movement can be described-as a first light pull which serves to partly disengage the sear 83 from the cocking nose 41. This light pull is continued until the trigger spur roller 104 comes in contact with the lower arm 102 of the forked searlink 87 the result of such trigger movement is illustrated in Fig. 25 where the dotted lines show the original on normal position of the mechanism and the full lines the result of this pull, the movement with respect to the trigger being represented by the angle 111. 4

Now the finger pressure on the trigger 86 must be increased due to the spur roller 104 being in contact with the lower arm 102 of the sear link 87 causing a sharp and distinct resistance for the finger to overcome; but as soon as thetrigger is pressed back a little fun ther the sear 83 becomes disengaged from the cooking nose 41, the friction of the said nose 41 on the sear 83 also ceases; and the finger pressure pressed the trigger back still furmuzzle opening is cha ther causing the trigger spur roller 104 to raise the sear link still higher thereby disconnecting the trigger nose 95 from the detent 101 as illustrated in Fig. 26 which shows the result of the first and second pulls mentioned above, the total trigger movement being represented by the angle 112. i

The cocking piece 41 being now free, un der the impulse of the main spring 32 is propelled forward and the sear 83 with its link 87 return to normal position under the tension of the spring 100, as illustrated in Fig. 27.

The trigger 86 can now be released and will return to its normal position whereat its nose 95 is again behind the detent 101 as shown by 'full lines in Fig. 5.

The rifle barrel is bfthe standard type it is bored and chambered for standard military or commercial ammunition. At its rear end it is threaded (113 Fig. 9) to be screwed into the receiver ring as at 11.4, Figs. 11 and 12 its other end is also threa d as at 115 and the cred as at 116 in Fig. 10.

The rifle as described abqve is capable of being used as a hand functioning arm in case the automatic features. aredisabled. Such automatic features which will now be de scribed includea gas retarder, shown in section at the muzzle end of the rifle barrel in F ig. 10, is so named because its purpose is to retard the gases issuing from the bore of the barrel after a shot is fired; in such a manner that the power 0% this retarded gas can be utilized to operate the gun.

More particularly, this gasretarder 1s made cylindrical in form, either inte "s1 with" -aving a said barrel or as an attachment, chamber 117 and, as shown, one end of which is screw threaded for engagement witlathe barrel thread 115'. I At the other end of this I to be installe caping through the aperture 118 into the atmosphere before the bullet passes through the said aperture to momentarily obstruct it.

On top of the main body of the gas retarder and integral-with it is the front si ht base 120 having a slot within which the sig t blade 121 is mounted and held in position as by means of a pin, not shown.

Atthe under side of the said gas retarder and slightly protruding from it is the gas outlet 122 havmg a hole 123 into which a tube 127 slidingly fits. This hole, moreover, is of sufiicient diameter and length to allow the tube to have a longitudinal movement therein to facilitate the assembling or disassembling same, as indicated by dottedlines 124 in Fig. 10, showing the end of the tube extending temporarily into the outlet 122.

The gas outlet communicates with and constitutes in efiect'a part of the chamber 117. At its end the gas retarder body surrounding the aperture 1.18 is formed to provide a bayonet seat 125 adapted to engage within the guard socket of a bayonet. From the gas retarder the powder gases are lead. to the power cylinder 126 (Fig. 9) ,by means of the gas tube 127 which is connected to said cylinder as by means of a union coupling 128; Within the power cylinder 126 is a piston 129, the pistoh rod 28 and surrounding said piston rod the action spring 69. Said piston is provided with an aperture inindicated by 130 to receive an end of the spring 69.

The power cylinder 126 is threaded as at 66 (Fig.9) for engagin thev threads 65 of the hand guard 132 meets the stock 131. These openings are desirably of the shape shown in Fig. 2 to allow ventilation tothe gun to prevent charging or overheating the wood. The hand guard andstock joint 134 referred to above, are located below the axis 135 of the barrel thereb allowing the complete action d as asingle piece on-the stock. :The action secured to the stock in the Same manner as the U. S. Springfield, 1903,

that is withtwo screws as illustrated in Fi 5. The up r band 136 is the UrS; standar The lower and 137, however, is iormedto' provide at one side thereof a D-shaped oflset r, scribed as follows, with reference to the accompanying drawings: Assuming the action 1s assembled closed, the trigger pulled, and

.the safety on, the action will then be as represented in Figs. 1', 2, 3, 4, 5, and 6.

' The operator holding the rifle in the usual manner, places his right-thumb on the fluted head 92 of the safety lever 81, Figs. 4 and 6, pulls it back and down. into ready position 94, Fig. 4; in so doing the sear link 87 is lowered from the position in which it is shown by dotted lines to that shown by full lines in Fig. 5 and the gate cover 75, Fig. 4 is released and thereupon opens against the stop 81 in a horizontal positionhas shown in-Fig. 8.

The operator then opens the action b means of the operatin handle 17, Figs. 3, and 8, drawing it bac as far as it will go, see Fig. 7, this exposing the opening or entrance to the magazine and uncovering the bolt stop 42 at the back of the magazine,

' allows the said stop 42 to raise in front of the breech bolt, said stop being pressed up by the magazine follower 'under the action of its spring 52.

The magazine can be filled by inserting one cartridge at a timeor the full quantity (5) by the use of a cartridge clip as is done in the Springfie1dthen drawing back slightly on the operating handle 17, thereby releasing the bolt stop 42 which was held up by the breech bolt assembly under the tension of the action spring 69 which was compressed by the opening movement. A

Said stop 42, now free, drops back into its recess under the action of its own springs 45, Figs. 23. The action now can close, let go the handle 17 permitting it to go forward, which will push a cartridge into the chamber and having, in the meanwhile, hooked the cocking piece 31 to the sear' 83 and locked the breech bolt to the barrel. a

' The rifle is now ready to fire. Should it be desired to carry the rifle loaded, press down the gate cover 75, Fig. 8 with the finger of the right hand and with the thumb of. the same hand push the safety lever 9192 into safe position, illustrated in Fig. .4, these-last two mentioned operations are done with a twist of the wrist. The action is ,now comtrance of sand, rain, dirt, etc.

" However, if it be desired pletely closed and -protectedjrom the erra cartridge into the magazine, draw back on safety lever 91 to ready, gate cover will agam open, and pull the trigger, which'is' similar} in action to that of the resent U; S.".s.' .r,vice

rifle although radically fieren't in prinjclptle, that is to sayit has alight-first all, a L er' which there is appreciable I ackward motion until the sear is released.

The firing pin having struck the primer of the cartridge in the chamber fires the shot,

the bullet is on its way down the bore of the barrel, the breech bolt 1 remains locked in position. When the bullet leaves the rifle bore,

however, the powder gases escape into the chamber of the as retarder trying to pass the bullet in its ight, but are turned back or deflected by the annular cavity at the end of the gas retard chamber 117, the bullet passing through the aperture 118 andmomen-v tarily obstructs it, the powder gas being then trapped cannot escape except through'the gas tube 127 into the power cylinder 126.

Within the cylinder the powder gases act to force the piston 129 back and through the medium of the piston rod 28, which is connected to the operating handle arm boss 27 Figs" 19 and 7 eflects the unlocking of the breech bolt.- projected from the aperture 118 into the atmosphere, but a part of the powder gases remain in the rifle bore, power cylinder and the communicating connections. By reason,

of the retarding'eflect which the gas retarder has upon the gases, the latter cannot escape into the atmosphere in as short a time as when no retarder is employed, this is due specifica1lyto the expansion and deflecting forces which' the gases are subject to before they can escape through the aperture 118. It is possible with my improvedsystem to utilize the gas force or power for relatively long periods oftime. The breech bolt being unlocked is pressed back by the power remaining inthe retarded gases, referred to above, acting on the power piston 129 and also on Meanwhile the bullet has been the fired shell completing the openingmovement of the breech bolt. When all the energy of the said powdergas'e's is spent, the rifle action is free, whereupon the action spring 69 returns the breech bolt forward to again push a cartridge from the magazine into the chamber and locking the-bolt. The trigger is now released and the rifle is again ready for firing.

If it is'desired to recharge the magazine after firing one or more shots, theoperating handle 17 is, drawn back'as far as it can go at the same time pressing upon the bolt stop plunger-rods 47, which projects on both sides of the magazine floor plate 138, and release the handle 17 which will hold the breech bolt open,;refill the magazine, draw back on the operating handle 17 and then let it go:

To employ the rifle as a single loader, press the operating handle 17 and release it or 01 the hand. To empty the maga- Izine, draw back on theoperating handle 17 action remains open.

asfar-as it will go, permit it to go forward slowly by holding the handle17 until closed, or partly so, repeating the process until the means spection or cleaning, place the safety ever 91 down at ready 94, Fig. 4, unscrew t 1e receivercap 56 by means of its handle 57-,58 then disengage the ower cylinder wing plug 68, Fig. 4, from the ayonet joint 67 by pushng. it orward and then turnin it up by meansof the thumb piece 70, Fig. 4. When in such. position the action spring '69 will push it back and the dowel 71 is in line to register with the hole'72' in the operating handle boss 27 will drop into it and hold said wing plug horizontally. Now by means of the operating handle 17 the complete breech bolt power-piston action spring assembly, shown in Fig.28, can be withdrawn from the receiver.

The barrel can now be inspected and cleaned from both ends and the power cylinder can be cleaned and inspected from the rear, as shown in Fig. 29. The breech bolt power-piston, action spring assembly (Fig. 28) is then replaced in the receiver, the Wing 1 plug 68 pushed. ahead and its thumb piece 70 turned down and the receiver cap replaced, making the rifleagai-n ready.

To dismount and assemble the action Remove the 'breech-bolt-power-piston action-spring assembly as explained above, then with one hand compress the action spring 69 toward the operating handle 17 to disengage it from the piston and, with the other hand,

unscrew the piston rod 28 from the operating handle arm boss 27, and remove from the piston rod 28 the wing plug 68 and'the action spring 69, I I

In all probability when the breech bolt assembly is removed from the receiver or during the operation mentioned above, the bolt 1 has receded into the operating slide 7 under the impulse of the main spring 32 which caused theoperating slide 7 ,to slide upon the bolt 1 or vice versa, and which are held apart by the operating lugs 8 and 9 resting.

on the ofiset shoulder 12 of the bolt grooves 11 and 12, Fi 17L However, if it has not,

make' it do so y rotating the bolt to the left (the only way it can turn when in that position) the main spring 32 .willthen pull' it back into the operating slide 7 Now holding the operating slide 7 on one hand, with the other pull "back the cooking piece 31 by hooking one finger on the cooking piece nose 41 and the thumb on the flange 4:01-1I1tilJSald cocking piece is out or to the rear of the side cheek 370i the bolt sleeve 21, then rotate it a e 7 rifle make it almostyfool proof as, for exquarter of a turn to the left and release the pull; the cooking. piece 31 will then rest upon 21 and rotating. the cooking piece 31 to right i or left said cocking. piece 31 will return between the bolt sleeve cheeks 37, as shown in Fig. 20. Now with one hand compress the main spring 32 toward the bolt sleeve 21 to disengage it from. the flange and with the other hand unscrew the firing pin 30 which will allow all component parts of the firing Lpin assembly to be examined separately.

To reassemble the action, proceed in the reversed order to that above exfplained and when the last operation is per ormed, that isthe screwing the piston rod 28 in position and before inserting the end of the action-spring 69 into the hole 130 on the piston 129, wind said spring by rotating it around the piston rod 28in an opposite direction to that in which the rod 28 was screwed, for one turn or more, then insert the spring end in its liole, which prevents the ,piston rod 28 from unscrewing and also serves to hold the wing plug 68 in its down position. 7

Now pull on the breech bolt head while turning it to the right (the only way it can be turned when pulling it) vuntil'the operat- L ing lugs 8 and 9 of the operating slide 7 rests upon the ofiset shoulder 12 of the bolt operating grooves 10 and 11. When the above named parts are thus arranged insert the breechbolt power piston assembly into the 7 receiver by guiding the power piston along the receiver side into its cylinder 126 and the breech bolt in the receiver grooves 116;

ush the handle 17 as far as it will go'thereby locking the'action; ush the wing plug 68 L ahead and turn down t e thumb piece into thebayonet joint 67; and finally put bn the receiver cap 56.

- The action is now fully reassembled ready to use. I

General remiss From the foregoing explanation; it will be seen that this semi-automatic shoulder rifle tools. The safety and trigger system used in this has a' rectilinear-type action and can be used f ample, when this, safet is at safeposition',

should any, one attempt to pull the trigger to fire, or to ascertain if the rifle can tired,

1 more causing the trigger spur roller'104= to m raise the sear link and detent 101 still further from the trigger nose 95, as illustrated in Fig. 27.

An'attempt, moreover, when safety is on the fire a shot by lowering the safet lever to ready position with the trigger held ack will also result in failure because, when the trigger is held back, the detent 101 is held up by the trigger spur roller 10 i (see Fig. 27); the lowering of the safety lever from safe to 2d ready position therefor cannot affect the sear trigger mechanism in any way, and the trigger must be released and again pulled before a shot can be, fired.

-While the action of this rifle rectilinear (straight pull) type, it has not the same. characteristics found in this type as heretofore constructed, its principles being difierentand with none of their disadvantages. Hitherto all straight 'pull actions 39', have been unsatisfactory chiefly because they lack the power to insert and extract car-' tridges from the chamber. v

This deficiency of power after considerable experimenting is found to be due to the systm used in their actions to prevent the bolt from rotating during its reciprocating moveinent. a I 1 The prior systems above referred to may be divided into four types, to wit: a

1st, the friction type which employs the simple expedient. or forcing the bolt along thereceiver races without obviating'the turning movement imparted to it by the slide, causing excessive friction with somemakes j of rifles and machine guns;

2nd, The catch-type employing a spring catch adapted to lock the bolt and slide during their mutual reciprocating motion} 3rd, The auxiliary rotating typewhich employ a cam in the receiver to give additional rotary motion to the breech bolt which causes it to engage some suitable threads or in a recess in the sleeve to lock the bolt for sliding and 4th, The helical groove type which employs- 1 a receiver havin helical grooves by means of which.v the 100 'ng lugs are given-a .suppleinenta'ry rotary motion in traveling in said 1 grooves to couple the bolt and slide together.

is of the the Rpssf during the opening and closing operation; 55

vent rotary motion .of the bolt in its reciprocating' movement) begin and'cease their functions at the precise moment when the maximum power of insertion or extracting is required, which is at the instant-the bolt is unlocked from the receiver and the recipro rotary movement is necessary, no catches nor other means are requisite to hold and'lock the bolt and slide together. The operating slide unlocks fully the bolt from the receiver andalso draws it back into the receiver -grooves. The bolt and slide are, not locked together and are reciprocated along the receiver grooves without any tendency to rotate about one another.

When the operating slide is pulled or pushed the operating lugs 8 and 9 are transferred from one side of the bolt grooves 10 and 11 to the other side without, however, imparting rotary motion to the bolt when the bolt is within the receiver grooves.

It will be noted that a neutral region is pro-, vided with respect to the operating grooves to allow longitudinal movement of the slide, onthe' bolt, or of both of them, is utilized not to prevent (as is done in the other actions mentionedabove) the rotary motion of the bolt, but to overcome said rotary motion at the instant the'bolt is unlocked from the receiver and until it is ready to lock again.

By axially engaging said bolt and slide in this act-ion wear will in no way affect its operation, but simply make this axial movement a little longer without affecting the action in the perfermance of its functions; whereas in the rot system as used for instance in a slight wear will render such action inoperative, as, for exam le, 'wear at the ed es of the internal teeth 0 the operating sl'i e, or onthe spiral ribs of the bolt will act to preventlthe latter rotating sufliciently in-its uhlockin' movements so that, when the bolt head-strikes the cam to give it the required auxiliary rotative motion to lock it to theopera tin'g slide, the; teeth in the sleeve fail to -registergwith the teeth spaces of the boltdt-lisaccordingly stuck, and it takes but little wearto do that. 4

The; actions using better those using helical races promote friction andare expensive to make.

In the present invention, the short longithe' catch system are no I tudinal movement afforded bythe neutral region provided in the respective grooves'to' axially engage the bolt groove with the oplcrating slide lugs, moreover, is automatically takenrup bythe-firing-pin main spring 32 causing the cooking piece 31 to press the operating slide 7 ahead and the bolt sleeve 21 to pull the bolt back causing a mutual contfagting or telescopic motion of the bolt and s 1 e.

Also making the operating slide movement somewhat short in locking the breech bolt compared with the unlocking movement, and incidently shortening the overall length of the combined bolt and slide in the unlocked position are important features when a rectilinear action is employed in a semi-automatic rifle, as it is possible to make the receiver shorter than it would be otherwise.

In a rifle action of this type, it will be seen by referring to Fig. 5, that the only part subject to great stress is the receiver ring 6 and the head of the bolt 7, the remainder of action, such as the receiver, is made very 1g it.

The breech bolt assembly in my improved action maybe of little weight, say-about 1 poundsmaking the actions extremely fast; in actual practice its movement is almost imperceptible and its recoil energy is so small that it is entirely absorbed by the action. spring 69 only when using extreme loads does the breech bolt assembly come into contact with the buffer in the receiver cap 56.

When firing this rifle none of the jerking and jarring of the weapon is felt by the rifleman as it is the case when firing the semiautomatic rifie of the barrel-recoil type or those using the inertia system of (blow-back) The automatic system used in my rifle is very flexible and will operate the action equally well when shooting either high or low pres-, sure cartridges in the same gun, that is'within certain limits or a variation of say, 10 grains of powder from maximum load.

It may be mentioned, an experimental gun has demonstrated that the gas retarder additional to its regular function, hereinbefore explained, embodies other beneficial characteristics, namely,it reduces the recoil of the gun an appreciable amount; it reduces the report of the gun perceptibly, and decreases the flash considerably. Furthermore, its structure acts as a guide for the cleaning rod to prevent the rod injuring, the muzzle of the rifle and also permits the bayonet to be attached so as to interfere'in no way with the proper operation of the rifle.

What I claim is,

1. In a fire arm, the combination of a receiver having locking-lug races and lug recesses, a bolt having a head adapted to engage in said recesses and to slide within said races, a longitudinally movable operating slide associated with said bolt, and connections comprising helical ofiset grooves on said bolt inter-engaging with helical lugs on said slide by which the bolt is rotated and reciprocated by the movement of the slide, the olfsetting of the respective grooves serve to provide neutralspaces within which the helical lugs are capable of reciprocating for a distance without imparting motion to the bolt.

2. In a fire arm, the combination of a bolt and an operating slide slidingly associated and provided with connections comprising helical lugs on said slide, helical ofi'set grooves on said bolt forming a neutral space for said lugs, said neutral space permitting retrograde longitudinal movement of the bolt with respect to the slide, a receiver having locking lug recesses, a head carried by said bolt and adapted to engage in said recess, a cam on said receiver adapted to be axially struck by said head to rotatably move said bolt to ,re-engage said grooves with said lugs and cause said head to rotate into locking engagement within said lug recesses when said slide is moved forward, and whereby said cam is rotatably struck by said head to axially move said bolt a short distance to the rear for primary extraction when said slide is retracted.

. 3. In a fire arm, the combination of a bolt I and an operating slide slidingly associated and provided with connections comprising operating lugs on said slide, helical oifset grooves on said'bolt to provide a neutral space for said lugs, said neutral space permitting retrograde longitudinal movement 'of the bolt with respect to the slide, a bolt sleeve, a main spring held under compression by said bolt and slide when said lugs are within said neutral space, a receiver having locking lug recesses, a head carried by said bolt adapted to engage said lug recesses, a cam on said receiver adapted to be axially struck by said head to rotatably move said bolt thereby reengaging said lugs to said grooves and cause said head to rotate into locking engagement within said lug recesses when said slide is moved forward, and whereby said cam is rotatably struck by said head to axially move said bolt a short distance to the rear for primary extraction when said slide is retracted.

4. In afire arm, the combination of a bolt and an operating slide slidingly associated and provided with connections comprising operating lugs on said slide, helical offset grooves on said bolt to provide a neutral spacefor'said lugs said neutral space permitting retrograde longitudinal movement of the bolt with respect to the slide, grooves and lugs, a bolt sleeve, a firing pin, a main spring surrounding said pin and held in compres-- ments f said bolt within said slide, a bolt move said bolt a short distance to the rear for primary extraction when said slide is retracted.

5. In a fire arm, the combination of. a bolt and an ope'rating slide slidably associated and provided with grooves formed to have a'neutral region and lugs, a receiver havmg lug recesses, 'a head carried by said boltand adapted to engage and be locked in said recesses, a firing pin, a bolt sleeve, a cocking piece associated with said slide and bolt,

anda main spring adapted to be compressed by said slide when retracted and to cause said bolt to recede axially within said slide when unlocked -tolongitudinally engage said bolt to the slide within said neutral region and to hold said main spring underv compression. 6. In a fire arm, the combination of a bolt provided with a head having locking lugs,'a

receiver provided with locking lug recesses, in which said locking lugs are adapted to engage and be locked, an operating slide provided with internal lugs, said slide slidingly fitting saidbolt, said bolt having externally spiral grooves arranged in'laterally offset relation with each other to provide a neutral region, said internal lugs being adapt- I ed to engage with the sides of the respective the said locking lugs to allow free passage to said ejector within such lug, a'spiral front face on said slotted lu'g, acam on said re- ,ceiver adapted to be axially struck by the slotted lug to rotatably turn said bolt, an operating slide slidingly fitting'said bolt, said 7 bolt having externally spiral grooves, said grooves being ofiset laterally with respect to each other to provide a neutral space on said bolt, and internal spirally arranged lugs in',the said slide'adapted to engage in the grooves with their sides and the shoulders w th their ends and to be free when i-within sald neutral space.

8. In a fire arm, the combination of a bolt providedwith a head having locking lugs, a receiver, provided with locking' lug recesses, 1n which said locking lugsare adapted to engage and be ,locked, an operating slide slidably fitting said bolt, operating lugs .provided on said slide,,s aid bolt having c mmunicating. spiral grooves arranged in at erally ofiset relationwith each other to provide a relatively wide areaof communicationbetween-said grooves, said wide area permitting inoperative axial and rotative movesleeve, a firing pin carried by said bolt, a

said operating slide is'retracted.

9. In a fire arm, the combination of a bolt provided with grooves, an operating slide provided with lugs slidingly associated with said bolt, said grooves including a neutral region through which said lugs are compelled to pass in each cycle of operation of said bolt, a firing pin, a bolt sleeve, and a main spring assoclated with said slide and bolt, and connections between said bolt and slide whereby said spring may be held under compres sion while said bolt and slide are permitted an axial movement on one another.

10. In a fire arm, the combination of a bolt and an operating slide slidingly associated with said bolt, lugs provided on said slide, a firing pin, a cooking piece, a mainspring, and a bolt sleeve associated with said slide and bolt, and connections on said bolt comprising longitudinally engageable and rotatably disengageable grooves with said slide lugs, saidconnections including a neutral region, said 'neutral region permitting longitudinal retrograde movement of the bolt with respect to the slide, said spring being adapted to be held under. compression while said bolt tating the compression of said spring when and slide are pressed together to be handled as a single piece.

11. In a fire arm, the combination of a bolt provided with a head having locking lugs, a receiver provided with looking 11 g recesses within which said locking lugs are adapted to be locked and unlocked, and longitudinal grooves in which said locking lugs can slide, an operating slide slidingly fitting said bolt,

a bolt sleeve, a firing pin carried by said bolt,.

a main spring surrounding said pin, a flanged cocking piece on said pin for facilitating the compression of said spring when said slide is retracted, and connections between. said bolt and slide, said connections comprising a neutral region with respect to said grooves permitting a longitudinal movement of said bolt within said slide whereby when the said slide is retracted the said bolt is unlocked and said main spring is allowed to retract the bolt within said slide thereby causing the said grooves to change their contact from one side and the rear of said slide lugs to the other side and front of said lug.

v 1 12. In' a -fire arm, the combinationlof a bolt provided with "a head having flocking lugs, a receiver provided with looking lug recesses with which said locking lugs are adapted to interlock and be locked, and longitudinal grooves in which saidTocking lugs can slide, an operating slide having operating lugs slidingl'y fitting said bolt; a bolt sleeve, a firing pin carried by said bolt, a

main spring surrounding said pin, a-flaiigedcocking piece on said pin for facilitating the compression of said spring when said slide is retracted, and connections between said bolt and slide, said connections comprising longitudinally engageable and rotatably disengageable grooves on said bolt having a neutral space in a portion of their length through said slide is retracted said bolt is unlocked and said main spring is allowed to retract said bolt within said slide thereby causing the said grooves to change their contact from one side and the rear of said slide lugs to the other side and front of said lug and thereby si glrtening the overall length of said bolt and s 1 e.

13. In a fire arm, the combination of a bolt provided with a head having locking lugs, a receiver provided with locking lug recesses with which said locking lugs are adapted to interlock and be locked, and longitudinal grooves in which said locking lugs can slide, an operating slide having operating lugs slidingly fitting said bolt, a bolt sleeve, a firing pin carried by said bolt, a main spring surrounding said pin, a flanged cocking piece on said pin for facilitating the compression of said spring when said slide is retracted, and connections between said bolt and slide, said connections comprising longitudinally engageable and rotatably disengageable grooves on said bolt, said grooves having therebetween a neutral region through which said operating lugs must pass in each cycle of their operation whereby when the said slide is retracted the said bolt is unlocked and said main spring is allowed to retract said bolt within said slide thereby causing the said grooves to change their contact from one side and the rear of said slide lugs to the other side and front of said lug and thereby annulling the rotations of said bolt When said slide is further retracted.

14. Inca fire arm, the combination of an operating slide, a bolt slidingly-associated with said slide and having an external thread, a bolt sleeve provided with an internal thread adapted to engage said external thread, cheek projections on said bolt sleeve, a firing pin, a main spring surrounding said pin, a cocking piece having fiat parallel sides adapted to slide between said cheek projections, a flange on said cocking piece engageable with said slide, and means whereby said cocking piece may be made to rest on the end of said cheek projections to facilitate the as sembling and disassembling of the said bolt sleeve firing pin, main spring, and cooking piece to or from the said bolt and; within the said slide. fi v 15. In a fire arm, the combination of a bolt provided with a head havingan extractor groove and locking lugs, a receiver provided with longitudinal grooves and lug recesses in which said lockinglugs may be reciprocated andlocked, an operating slide slidingly associated with said bolt and having guides adapted to slide in said receiver grooves, a combination groove-and-socket in one of the said guides, and an extractor adapted to be rotatably engaged by said bolt extractor groove and to axially engage said combination groove-and-socket on said slide.

16. In a fire arm, the combination of a receiver in which operates and slides a breech bolt, said receiver having a magazine opening, a magazine'havin a follower actuated.

by a spring adapted to eed cartridge through said opening, an housing on said magazine wall, a pawl in said housing having at each side a tubular guide adapted to guide said pawl and extending through the-magazine floor, springs in said guides to normally hold said pawl within said housing, and a finger projection on said follower adapted to en gage and raise said pawl out of said housing to in front of said breech bolt when the latter is fully retracted'and whereby said pawl will return within said housing when said follower is depressed.

17. In a fire arm, the combination of a receiver provided with longitudinal grooves having a gateway, a slide provided with guides and a handle-arm adapted to slide in said grooves and gateway, a spring actuated gate cover hingedly connected to said receiver and adapted to close said gateway and a safety lever adapted to hold said gate cover in its closed position.

18. In a fire arm, the combination of a receiver provided with longitudinal grooves having a gateway, a slide provided with guides and a handle-arm adapted to slide 1n said grooves and gateway, a safety lever and a spring actuated gate cover adapted to close said gateway and to lock said safety lever when the latter is in safe position.

19. In a fire arm, the combination of a receiver provided with longitudinal grooves having a gateway, a slide provided with guides and a handle-arm adapted to sl de in said grooves and gateway, a gate cover hinged to said receiver, a stop on said receiver, springs associated with said receiver and the gate cover tonormally hold the latter in its open position and against said stop.

20. In a fire arm, the combination of a receiver provided with lug recesses and longitudinal grooves having a gateway, a power cylinder on said receiver, a bolt in said receiver having a head adapted to look within said recesses, a, slide slidingly associated with said bolt and adapted to slide in said grooves, connections comprising interlocking grooves on said bolt having a neutral region and lugs ori-said slide which are compelled to pass through said neutral region when the bolt is rotated and reciprocated by means of the slide, a handle-arm on said slide adapted to slide within said gateway, a rod on said arm, 

